Igniters for explosive charges which can be used in an automotive safety system are of course known. Such igniters, known also as explosive squibs, are connected to electrical conductors which are connected to a control device which, in case of a crash, can apply the potential to the conductors or lead to firing the squib. The firing of the squib, in turn, ignites an explosive charge which inflates the folded bag or drives an element, for example, a piston, to tighten the belt. For that purpose, the squib was disposed in a housing and the explosive force from the squib was directed toward the explosive charge which was to be ignited. While the explosive charge or main charge was thus ignited, the force of the explosion of the squib had a tendency to act in the same direction as the explosion of the charge, resulting in a transmission of energy toward a free space. To a certain extent the explosions drove particles of the charge in the direction of this free space and in which these particles did not completely burn. It was required, therefore, to increase the size of the charge to take into consideration the fact that a portion thereof, driven away from the squib by the explosive force thereof and the explosion or the main charge, did not contribute to the production of energy which in turn was utilized to expand the air bag or to displace the member for tightening the belt.